Development And Application Of Online Monitoring Device For Dissolved Gas In Transformer Oil Of Shijiazhuang Power Grid

As the core equipment of electric power system,the condition of the transformer is healthy or not,which is significant for the maintenance of the safety of the power system.The technology can effectively capture the early signs of transformer fault of transformer oil dissolved gas analysis,especially with the application of online monitoring technology,can achieve better predictive maintenance of transformer,is one of the most important technologies to reduce the transformer failure rate.In this paper,the present situation and development trend of dissolved gas chromatographic analysis technology and domestic exterior line monitoring technology are analyzed,and the principle and work flow of dissolved gas analysis technology and on-line monitoring device are introduced in this paper.An on-line monitoring device for dissolved gas in transformer oil based on dynamic headspace gas chromatography,high performance composite chromatography separation column and micro bridge detector is developed.The online monitoring device of five parts analysis system,temperature control system,automatic control system,communication system,monitoring workstation by chromatography,can be realized in transformer oil CH₄,C₂H₂,C₂H₄,C₂H₆,H₂,CO,CO₂,H₂ O,O₂ and N₂ ten components detection.In this paper,a software system is designed based on the SERVER SQL 2000 database of dissolved gas in the oil dissolved gas on-line monitoring device.The software system can on-line monitoring of the working process of the automatic control device,comparing the collected data with preset attention value,analysis method of three ratio method,David triangle method,three-dimensional graphic method and other advanced diagnosis intelligent diagnosis and send alarm signal.It is able to detect and diagnose the incipient faults of the transformer in time,and monitor its development,and make up for the deficiency of the traditional off-line chromatographic analysis.This paper summarizes the common problems and matters needing attention in the field installation and operation based on the experience of the application of the on-line monitoring device for dissolved gas in oil.This paper introduces a device of the discovery of transformer oil paper capacitive bushing flange and CT barrel based on between floating voltage fault cases,through the comparison of the case of the analysis of the experimental data,the reliability of the device monitoring data and diagnostic results,the economic and technical evaluation of the application of gas dissolved in oil online monitoring device.